Ⅰ. Research background of diesel fuel lubricity improver
In the early 1990 s, with the improvement of refined degree of diesel, sulfide content was required to be lower and lower, accidents of rapid wear failure of diesel engine high pressure oil pump and fuel injector constantly appeared in many countries, such as Sweden, Canada, and part region in American. If large-scale fuel pump was in failure, pump will be adhesive wear, then performance of the pump dropped rapidly to not be able to use. The accident warns people that diesel fuel lubricity began to decline.
Anti-wear lubricity is influenced by polycyclic aromatic hydrocarbons, oxygen impurity, nitrogen impurities and sulfur compounds in diesel; strength of diesel lubricity depends on the content of anti-wear material. Polycyclic aromatic hydrocarbons, and nitrogen compounds have good anti-wear effect, while sulfide do not antiwear, instead of promoting wear. Sulfide in diesel is excited in aromatic hydrocarbons and polycyclic aromatic hydrocarbons in the form of heterocyclic, so in the early 20th century, diesel sulfur removal was advocated since sulfide seriously leaded to environment pollution, meanwhile removed aromatic hydrocarbons and polycyclic aromatic hydrocarbons and some components having lubricity. Engine with diesel will appear wear and damage with the decrease of sulfur content, shorten its service life. To improve the wear resistance of low sulfur diesel fuel becomes an important issue urgent needing to study.
The problems about low sulfur diesel can be solved from two aspects:
The cost improving equipment of engine is huge, and the project takes a long time, so foreign oil companies mainly use the method of adding antiwear additive to improve the lubricity of diesel and reduce equipment wastage. It is the most economic and effective method to add the anti-wear additive for improving the diesel fuel lubricity.
Since our country joined WTO, oil marker gets the further open, and the quality of diesel must be in line with international standards. Since July 1, 2007, national standard equivalent to euro IV is conducted, the diesel will be developed in the direction of ultra low sulfur and low aromatics, so to study the high-efficiency, low toxicity antiwear additive having good application value to stop the diesel engine wear is the inexorable trend of domestic low sulfur diesel oil development.
ⅡFunctional mechanism of diesel fuel lubricity improver (anti-wear additive)
Antiwear additive of low sulfur diesel is the substance having polarity, add a little of anti-wear material in diesel, which can attach to the metal surface based on acting force between intramolecular and intermolecular to generate firmed organic adsorption film so as to make the capacity of low sulfur diesel not easy to adhere.
Ⅲ. Preparation of equipment and indicators of low sulfur diesel fuel lubricity improver (anti-wear additive)
1. Equipment: ball-on-disk film tester and high frequency reciprocating tester (HFRR)
2. Indicators: wear scar diameter of steel ball tested is as index to evaluate antiwear propert. At present, anti-wear performance testing index has been stipulated in diesel index for city motor use with the wear scar diameter no more than 460μm.
3. Evaluation method for performance of diesel.

The anti-wear additives shall be not only required to ensure antiwear of border, but the additive must be efficient, not producing obvious negative impact on main performance of diesel, such as oxidation stability, detergency, corrosion resistance, water separation property and environmental performance. Therefore, performance of diesel shall be evaluated , and the method is as follows:
Evaluation method for performance of diesel

2. It shall be stored in a cool and ventilated environment to prevent exposure and be away from the fire. It can be stored for two years under the conditions of room temperature and sealed storage.Ⅵ Application method
1. Produce Ⅲ standard diesel, 100～150ppm dosage is recommended
2. Produce IV standard diesel, 150～300ppm dosage is recommended
3. Add the dose to diesel, mix evenly through circulation. The dose shall be diluted with diesel, then added to diesel.
Ⅶ Packaging and storage
1. Packaged with plastic or galvanized iron barrel (net weight is 170 kg/barrel)

2. It shall be stored in a cool and ventilated environment to prevent exposure and be away from the fire. It can be stored for two years under the conditions of room temperature and sealed storage.